Endeavour thundered from NASA’s Kennedy Space Center in Florida at 9:48 p.m. EST, trailing a brilliant pillar of fiery exhaust as it steered a northerly course. The storm clouds that had been forecast veered safely away.

Following a series of maneuvers by the shuttle, the two big spacecraft are to link nearly 250 miles above the Earth on Saturday afternoon. Over five days, the seven Americans and three Russians aboard the joined spacecrafts will exchange nearly four tons of food, water, clothing, scientific equipment and other supplies.

The crew includes flight engineer Michael Anderson, a graduate of Cheney High School.

Endeavour also will deliver astronaut Andrew Thomas to Mir, who will become the last of seven Americans assigned to live and work aboard the outpost. The 46-year-old mechanical engineer plans a four-month visit, during which the United States will exceed two continuous years in Earth orbit.

Thomas will replace David Wolf, the 41-year-old physician and engineer, who blasted off for Mir in late September. He will conclude a 128-day visit with Endeavour’s return to Earth on Jan. 31.

Thomas plans more than two dozen experiments in disciplines that range from medicine and biotechnology to physics and Earth observations.

Among the experiments with the highest priority is an effort to artificially culture human breast cancer tissue in a small rotating incubator called a bioreactor. Medical researchers hope the effort will enable them to closely study the development of the nutrient supplying blood vessels as the tumor mass develops artificially.

The experiment may enable them to develop treatments for the disease that effectively starve the tumor, possibly avoiding the need for surgery, radiation or chemotherapy.

Endeavour’s crew is led by mission commander Terry Wilcutt and mission specialist Bonnie Dunbar, both making their second voyages to Mir.

They are joined by Anderson, pilot Joe Edwards, load master James Reilly and Russian cosmonaut Salizhan Sharipov, all spaceflight rookies. Thomas logged a previous shuttle flight in 1995.

The shuttle astronauts plan experiments of their own during their nine-days aloft, among them a novel space aquarium. The tank aboard Endeavour houses four pregnant swordfish and 200 smaller ones. The enclosure is equipped with snails and plants as well as water.

“It’s a closed system,” said Anderson, who will tend the facility. “Hopefully, the fish will eat. They will produce waste products as nutrients for the plants. These plants will produce oxygen for the fish to breath.”

“With this type of set up, we may be able to raise fish in orbit during long spaceflights,” Anderson said. “It may be possible to harvest fish as a source of high protein food.”